A detergent dispensing device for an automatic washing machine, the device having a cartridge with a plurality of chambers to accommodate a detergent composition, a selecting means to selectively expose each chamber to wash liquor allowing the detergent, in use, to be washed out of the chamber; a manual operating means being movable from a first position to a second position for loading mechanical energy into the device which provides a restoring force for the operating means, and a thermal element to retain the operating means in the second position, the thermal element being arranged to move when subjected to an elevated temperature prevailing in an interior of the machine during a wash cycle, thereby moving the operating means or releasing the operating means, the operating means being arranged to advance the selecting means to an adjacent chamber as the cartridge remains stationary.